Parry: How would you improve it?

[Zojha]

But Parry will only be appealing if the game go through some major rework to make tanks WANT defensive stats.

This pretty much.

The primary purpose of mitigation is to prolong the fight. The same goes for healing. So typically, the dynamic works by making the encounter a race against the healers mana ressources, with mitigation serving as a way to conserve mana by simply taking less damage and thus, reducing the strain on the ressources. This ultimately gives every fight an innate DPS check, because even with good mitigation, ressources at some point run dry and the boss needs to die.

In this game however, mana management is trivial and consequently, DPS checks cannot rely on this innate mechanic and instead are simply hard enrages/wipes. This skews the favor towards damage, because mitigating more damage is pointless - it does not give you more time to beat the boss, which is its purpose, so it's without a purpose.